i have a mercury 9.8 outboard. i don't know the year the serial number on the motor is 4546798. anyway the problem i am having is that there are times when the thing just doesn't want to start, and this does not always occur on the first start of the day. yesterday for instance i started it about 5 times and on the sixth time it took me 15 minutes of pulling and finally disconnecting the gas tank to get it started. once its started it runs fine but there are times when i have to pull on it 30 or 40 times. i just changed the plugs in the motor. could this be a carb issue or something bigger? thanks for the help